Gelatin compositions containing salts of half esters of sulfosuccinic acid as coating aids therefor



bination in which saponin is empolyed. r

include highly. branched chain alkyls. our invention will appear herein United States Patent O This invention relates to gelatin compositions containing certain salts of half esters of sulfosuccinic acid as coating aids therein.

In the application of gelatin coatings in the preparation of photographic elements such as to film base or paper,

either in the form of a single layer or as multi-layers coated simultaneously, the addition of a suitable-coating aid permits the obtaining of dried coatings free of such coating defects as repellencies, pencil line streaks and the like. However, dried coatings involving the usual synthetic surfactants are characterized by surface slipperiness resulting in handling difficulties and/or inadequate rewettability. The latter introduces difiiculties in the processing of photographic products Surfactants or coating aids which cause coatings having good rewettability often give a gelatin layer with a slippery surface.

In order to take advantage of the superior coating properties of synthetic coating aids, especially in simuitaner ous multi-layer applications, it has been desirable to use these agents in combination with saponin to achieve both adequate surface roughness and satisfactory revvettability. However, saponin, being a naturally occurring substance of. considerable variation from batch .to batch, its use may cause an increase in fog, a change in photographic sensitivity or sometimes may not even improve the rewettability of the gelatin layer obtained. Because of these variations in the quality of saponin, it is desirable that the combination of characteristics desired be obtained by the use of a single synthetic coating aid rather than by a com- One object of our invention is to provide coating aids which when employed in gelatin coating compositions will give layers having adequate rewettability without any apof our invention is to provide gelatin coating compositions which esterify one carboxyl of the sulfosuccinic acid Other objects of We have found that gelatin compositions containing alkali metal salts of certain half estersof sulfosuccinic acid 'in whichbranched chain alkyl alcohol radicals satisfy one of the carboxyl groups of the sulfosuccinic acid give gelatin coatings having adequate rewettability without any appreciable drop in frictional characteristics. It is desirable that the coating aid be present in the gelatin composition in an amount of 0.510%, 'based on the wegiht of the gelatin. The gelatin compositions in accordance with our invention may bethose which are used merely .to coat multiple gelatin layers which contain no sonsitized addenda or they may be gelatin-silver halide photographic emulsions.

The gelatin compositions in accordance with our invention are particularly useful in. the preparation of photographic elements, such as in coating "ice Patented Aug. 17, 19 65 and a developer spread greater than 4.00 cm? to give products which are satisfactory for actual use.

The coating aids in accordance with our invention are the sulfosuccinic acid ester salts having the formula 0 o Q(OC2H4)DO CH2CH( JOM SOgNa in which n is 0 to 10, M is an alkali metal substituent and Q is either a branched-chain. alkyl radical of 10-l 6 carbon atoms having at least 3 points of branching or in which R is a branched-chain alkyl radical of 8-14 carbon atoms having at least 2 points of branching. Examples of materials of this nature are the sodium salts of half esters of sulfosuccinic acid, having on one of the carboxyls a radical derived from p-tertoctylphenoxyethanol or its ethylene oxide derivatives and sodiumsalts of half esters of sulfosuccinic acid in which one of the carboxyls is esterified by tridecyl alcohol or its ethylene oxidederivatives. Tridecyl alcohol is a commerical material prepared from te'trapropylene by means of the oxo reaction and is a mixture of primary bra11ched-chainC alcohols. -Compounds of this nature may be prepared as v follows:

preciable decrease of surface roughness. Another object r ing the formula TRIDECOXYETHYLSULFOSUCClNATE (SODIUM SALT) A mixture of 38.9 parts of maleic anhydride and parts of tridecoxyethanol was heated onra'stearn bath with occasional stirring untila homogeneous product resulted. Heating was continued for an additional 5 hours, whereupon the adduct was poured into a well-stirred solution of 50 parts of sodium sulfite in 500 parts of water. A gelatinous mixture resulted. Complete solution was effected by heating his mixture on the steam bath for an hour with stirring. A- solution of a compound hav- C H OCH CH OCOCH CH(COQNa)SO Na was obtained. The resulting water to any desired strength.

r Derivatives from tridecoxydiethoxyethanol,

c n o(crr cn oncrncn on and from tridecoxypentaethoxyethanol,

e n o cn cn ohcn cn on P-TERT-OCTYLPHENOXYDIETHOXYETHYL- SULFOSUCCINATE (SODIUM SALT) In preparing this product 134.2 parts of p-tert-octyl phenoxydiethoxyethanol, 38.9 parts ofmaleic anhydride and 50 parts ofsodium sulfite were used in accordance solution canbe diluted with.

manner to a flat, dried coating surface.

redissolved to give a clear solution.

The various compounds prepared as described above and with varying proportions of ethylene oxide units (such as 1, 3, 5, 6 7.5 and the like) were incorporated in gelatin compositions in various proportions. Coatings prepared from those compositions exhibited good d veloper spreads and coefficients of friction greater than 0.300. Developer spread is determined by measuring the area covered by 1 ml. of developer delivered in a standard A developer spread greater than' 4 cm. is considered adequate for de- 'veloper wettability i n photographic uses.

The following examples illustrate coating operations in accordance with our invention:

Example 1 There was simultaneously applied to paper a gelatins ilver halide photographic emulsion and a clear gelatin overcoat by means of the hopper technique as described in U. S. Patents No. 2,761,417, 2,761,418 and 2,761,791

of T. A. Russell. The surfactant used was disodium ptert-octylphenoxyethylsulfosuccinate except in the control in which case no coating aid was employed. The various coated papers obtained were tested for developer spread and co'efficient of friction and the following results were obtained:

Surfactant concentration Developer Coeificient Emulsion Overcoat spread (cm!) of friction coat composition composition (g./ib.)

0. 13 0. 4. 0. 540 0. 0. 5 4. 15 0. 507 0.5 0.5 4.15 0.497 None None 3.14 0.540

Example 2 A coating method was carried out similar to that in the preceding example except that disodium p-tertoctylphenoxydiethoxyethylsulfosuccinate was used as the coating aid, except in the case of the control wherein no surfactant was employed. The proportions of coating aid used and the developer spreads and coefficients of friction obtained with the various papers were as follows:

Surfactant concentration Developer Coeiiicient Emulsion Overcoat sprcad(cm. oi friction co I composition composition (glib O. 13 0. 5 4. 90 0. 551 0. 25 0. 5 5. 72 0. 551 .0. 5 .0. 5 6. 16 0.517 None None 3. 80 0. 660

. Example 3 A coating procedure was carried out similar to that described in Example 1, except that the coating aid 4 used was sodium p-tert-octylphenoxytetraethoxyethyl sulfosuccinate except in the case of the control wherein no coating aid was used. The proportions of surfactant employed in the emulsion layer and the overcoating layer and the developer spreads and coefficients of friction of the various papers were as follows:

Surfactant concentration Developer Cocflici ent l0 Emulsion Overcoat spread (cm of friction coat composition composition (g./ib.)

0. l3 0. 5 6. 60 0. 435 0. 25 0. 5 6. 10 0. 430 0. 5 0. 5 5. 72 0; 457 None None 3. 14 0. 574

Example 4 Paper was coated by a multi-layer coating technique as described in Example 1, except that the coating aid used in each case, except the control, was disodium p-tertoctylphenoxypolyethoxyethylsulfosuccinate. The proportions of coating aid employed in the various coatings and the developer spreads and coeflicients of friction obtained in each were as follows: 1

Surfactant concentration 7 Developer Coeflicient Overcoat spread (cm!) of friction composition (glib.

0. 5 10.70 0. 375 0. 5 9.08 0. 398 0. 5 11.90 0.320 None 3. 46 0. 606

Example 5 sodium tridecylsulfosuccinate was used as the coating aid in every case except in the control. The proportions of coating aid used and the developer spreads and coefli cients of friction of the papers obtained were as follows:

Surfactant concentration Developer Coefllclent Overcoat spread (cm?) of friction composition (glib.

0.5 4.52 0.517 0.5 4. 52 0.474 0.5 4.90 0.457 None 3.14 0.540

Example 6 A coating procedure was carried out as described in Example 1 except that disodium tridecoxyethylsulfosuccinate was employed as the coating aid in every case except in the control. The proportions of coating aid ernployed and. the developer spreads and coefficients of friction of the various photographic papers obtained were as follows:

Surfactant concentration 7 Developer Cocfi'icient Emulsion Overcoat spread (cm?) of friction coat composition composition (g. lib. (gJib 0. 13 0. 5 4. 52 0. 517 0. 25 0. 5 4. 52 0. 463 0. 5 0. 5 4. 0. 419 None None 3. 14 0. 540

In a coating operation as described in Example 1 Surfactant concentration Coeflicient of friction Developer Emulsion Overcoat spread (0111.

coat composition composition (g./lb.)

ton-

cum

Example 8 The operation as described in Example 1 was repeated except that disodium tridecoxypentaethoxyethylsulfosuccinate was employed as the coating aid. The proportions of coating aid used and the developer spreads and coefiicients of friction of the various papers resulting were as follows:

Surfactant concentration Coeflicicnt of friction Developer Overcoat spread (cm?) composition Emulsion coat composition Example 9 A single-layer hopper coating was applied to film base by a conventional hopper technique using coating aid at the concentration of 0.22 g./lb. of wet coating melt. The coating aid used was sodium p-tert-octylphenoxyethylsulfosuccinate (I). The characteristics of the material obtained as compared with the control in which no coating aid was used were as follows:

Surfactant Repellencies Mottle Longitudinal (25 ftfl) Streaks Slight-I- 4 Slight 3 Slight.

Slight Control I Example 10 Surfactant Mottle Longitudinal Repellencies IL Streaks Sligl Very slight. Very slight Very slight.

Example 11 A single-layer hopper coating was applied to film base by conventional hopper technique using coating aid at the concentration of 0.22 g./lb. of wet coating melt. The coating aid used was sodium tridecoxyethylsulfosuccinate (III). The characteristics of the material obtained g as compared with the control in which coating aid was used were as follows:

Surfactant Repellencies Mottle Longitudinal (25 ftfl) Streaks Control 4 Slight Slight. 0 Very slight"--. Slight+.

We claim:

1. A composition of matter comprising gelatin containing as a coating aid therein a compound having the formula r in which n=010, M is an alkali metal substituent and Q is a substituent selected from the group consisting of the branched-chain alkyl radicals of 10-16 carbon atoms with at least three points of branching and the alkaryl radicals,

R being a branched-chain alkyl radical of 8-14 carbon atoms with at least two points of branching,

2. A composition of matter comprising gelatin containing as a coating aid therein a compound having the formula in which n=0-10, M is an alkali metal substituent and Q is an alkaryl,

R being a branched-chain alkyl radical of 8-14 carbon atoms with at least two points of branching.

4. A composition of matter comprising gelatin containing as a coating aid therein alkali metal salt of tridecoxyethylsulfosuccinate.

5. A composition of matter comprising gelatin containing as a coating aid therein alkali metal salt of p-tertoctylphenoxydiethoxyethylsulfosuccinate.

6. A composition of matter comprising gelatin containing as a coating aid therein alkali metal salt of ptert-octylphenoxytetraethoxyethylsulfosuccinate.

7. A composition of matter comprising gelatin containing as a coating aid therein an alkali metal salt of trid ecoxypentaethoxyethylsulfosuccinate.

8. A gelatin-silver halide photographic emulsion containing as a coating aid therein a compound having the formula CHr-CO O (C2II40)11Q GEL-C 0 CM 7 in which n=010, M is an alkali metal substituent and References Giteti by the Examiner Q is a substituent selected from the group consisting of UNITED STATES PATENTS the branched-chain alkyl radicals of 1016 carbon atoms 2,028,091 1/36 Jaeger 8-127 alt least three points of branching and the alkaryl 5 2,240,476 Simmons et a1 6 109 a 2,647,925 8/53 Gilbert et a1. 260-613 2,940,854 6/60 Gray 9694 3,026,202 3/62 Knox et a1. 9644 C FOREIGN PATENTS 10 551,246 2/ 43 Great Britain.

128,286 7/59 Russia.

R being a branched-chain alkyl radical of 8-14 carbon NORMAN TORCHKN P'rimmy Exammer atoms with at least two points of branching. PHILIP MANGAN, m r- 

8. A GELATIN-SILVER HALIDE PHOTOGRAPHIC EMULSION CONTAINING AS A COATING AID THEREIN A COMPOUND HAVING THE FORMULA 